Growth And Dielectric Properties Of Ta2o5 Single Crystal By The Floating Zone Method

Large Ta2O5 single crystal with high-dielectric permittivity was successfully grown by floating zone (FZ) method under air atmosphere. The grown crystal that has been obtained was typically about 8 mm in diameter and 90 mm in length. The crystal growth parameters were optimized. The crystal symmetry, characterized by means of X-ray diffraction (XRD), was found to be tetragonal. The relative permittivity and loss tangent along growth and [001] direction were measured in the temperature range between -200 degrees C and 200 degrees C, which showed a strong dielectric anisotropy. At a frequency of 1 MHz and 20 degrees C, the dielectric permittivity along the growth direction and [001] direction are 81.17 and 25.04 respectively. The stabilization of high-temperature phase can explain the dielectric enhancement.